City expanding ShotSpotter program to help detect gunfire

New York City is spending $1.5 million to expand a year-long pilot program that uses microphones to detect gunfire, officials said Monday.

In all, 300 of the devices will be installed across 15 square miles in precincts with the highest rate of shots fired and gunshot victims, said Mayor Bill de Blasio, who announced expansion of the program at NYPD headquarters.

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So far, sensors have gone live in the Bronx and next week, they’ll be operational in Brooklyn. Police commissioner Bill Bratton said he expects to expand the program to other parts of the city once the pilot program ends.

De Blasio said the ShotSpotter program will help relay more information to police officers faster than the current system, which often relies on citizens to report gunfire to 911 operators, who then contact the police.

“What you get with ShotSpotter is real-time information so the police can respond so much faster. It increases the chances of catching the shooter” and could prevent retaliatory shootings," de Blasio said. "The audio senses detect gunfire, pinpoint the shots to literally, within feet of where they have occurred and that gives the police the ability to get to the scene.”

De Blasio said the new technology “is going to send a message out over communities that if you fire a weapon the police are going to know instantly so there’s going to be a deterrent effect.”

Bratton said he expected the number of reported shootings to increase once the ShotSpotter devices are operational, since they will alert the police to gunfire that, in many cases, goes unreported.

The ShotSpotter sensors are connected to thousands of cameras set up around the five boroughs as part of the city’s Domain Awareness System, which collects a wide arrange of information used by law enforcement personnel. When gunfire is detected by ShotSpotter sensors, nearby cameras will be engaged to review footage from moments before the shots were fired.

“Our officers will go into a situation with a much fuller picture of what they’re going to encounter,” de Blasio said. “They won’t go in blind. They’ll have a lot of information as they approach the scene of a crime.”

This isn’t the first time the NYPD sought to use technology to detect gunfire.

In 2011, the department tested another form of audio gunfire detection, but the pilot program failed because it did not distinguish between genuine gunfire and similar sounds, like a car backfiring.

There are major differences between the technology tested in 2011 and today’s Shotspotter, said Jessica Tisch, the NYPD's deputy commissioner for information technology.

First, she said, today's technology is better and more sensitive than it was four years ago. (Bratton said in the future, ShotSpotter will be able to identify the kind of gun being fired, and whether multiple shots are being fired from different guns.)

Second, there is a higher threshold needed to be met before the sensors send a report of gunfire. ShotSpotter needs to detect the sound of gunfire on three sensors—the earlier system required only one sensor. Finally, there is a human backstop, Tisch said. ShotSpotter sensors in New York City will send alerts of gunfire to a ShotSpotter technician in the company’s office in California who will verify whether the report is accurate, before forwarding the message to the NYPD. The ShotSpotter verification takes about 30 seconds, Tisch said, and helps reduce false positives.

Before returning to the NYPD in January 2014, Bratton was a member of ShotSpotter’s board of directors. He divested from the company before becoming NYPD commissioner.